Proximal loaded disposable loading unit for surgical stapler

ABSTRACT

A loading unit removably loadable into a surgical instrument positioned within a body of a patient having an elongated member, first and second jaws at a distal portion and a firing mechanism movable within the elongated member to effect firing of fasteners into the tissue clamped between the first and second jaws. The loading unit is insertable into a proximal opening of the instrument and through a lumen in the shaft of the instrument while the instrument is positioned in the body of the patient. The first and second jaws extend distally of the shaft of the instrument and the loading unit is actuable by the instrument. A surgical instrument to receive the loading unit and a method for reloading the instrument are also provided.

This application claims priority from provisional application Ser. No.62/553,297 filed Sep. 1, 2017, and from provisional application Ser. No.62/616,045, filed Jan. 11, 2018. The entire contents of each of theseapplications are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This application relates to surgical staplers, and more particularly, toloading units for surgical staplers.

2. Background

Surgical staplers are used in various medical applications where adevice is needed to simultaneously join and dissect anatomical tissue.The staplers are generally used in either open or minimally invasive,e.g., laparoscopic, surgical procedures. Surgical staplers typicallyrequire the user to actuate the device, dissecting and joining a givenlength of anatomical tissue as actuation advances a plurality of rows ofstaples through tissue and advances a knife to cut tissue between therows (lines) of staples. The surgical staplers are mostly multiple use,single patient devices which means the same instrument can be reloadedmultiple times with a fresh array of staples in a single surgicalprocedure. Thus, the stapler can be reloaded with new fasteners once thefasteners have been spent (fired) to provide multiple firings using asingle stapler.

Since the staples are contained at the distal end of the stapler,current surgical staplers require distal loading of the staples toachieve multiple firings. This means the clinician needs to remove theentire surgical stapler from the surgical site, i.e., removed not onlyfrom the target tissue area but from the patient's body altogether, inorder to reload the surgical stapler with fresh fasteners for subsequentapplication (firing) of staples to tissue. This also requires the user,after loading the new staples, to reinsert and reposition the surgicalstapler device back to the target surgical site after each reloading offasteners. The withdrawal and repositioning of the surgical staplerdevice adds time and complexity to the procedure, and in certainprocedures it might be difficult for the clinician to place the surgicalinstrument at the exact previous surgical site. Additionally, thewithdrawal and repositioning of the instrument becomes time consuming inrobotic surgery when the robot arm has achieved fine positioning and thestapler needs to be repositioned each time after the stapler iswithdrawn and reloaded.

It would be advantageous to provide a surgical instrument whichovercomes the drawbacks associated with current reloading of surgicalinstruments to achieve multiple firings of a stapler in a singlesurgical procedure.

SUMMARY

The loading units and instruments of the present invention overcome thedeficiencies and disadvantages of the prior art. The present inventionadvantageously provides loading units and surgical instruments thatenable the loading units to be removed and inserted while the instrumentremains in the patient's body, thus avoiding the need to remove andreinsert the instrument when additional instrument function is desired.

In accordance with one aspect of the present disclosure, a surgicalfastener applier is provided comprising a housing having a proximalopening at a proximal portion and a lumen extending longitudinallydistally from the proximal opening and an elongated shaft extendingdistally from the housing and having a lumen dimensioned to receive aloading unit. The loading unit has an elongated member, first and secondjaws at a distal portion and a firing mechanism movable within theelongated member to effect firing of fasteners from the loading unitinto tissue clamped between the first and second jaws. The loading unitis insertable into the proximal opening of the housing and through thelumen of the housing and through the lumen of the elongated shaft toexpose the first and second jaws from a distal end of the elongatedshaft.

In some embodiments, the loading unit includes a cartridge containingthe fasteners, the cartridge removable from the loading unit afterfiring and replaceable with another cartridge having fasteners.

The loading unit can be removed from the surgical fastener applier whilethe surgical fastener applier remains in a body of a patient. Theloading unit in some embodiments is removable by proximal withdrawalfrom the lumen of the elongated shaft and proximal opening of thehousing.

In some embodiments, the housing has a compartment to receive a powerpack having a motor and an engagement member removably engageable withthe firing mechanism of the loading unit when the power pack ispositioned in the compartment to effect powered movement of the firingmechanism from a first position to a second position to fire thefasteners. In some embodiments, the power pack includes a secondengagement member removably engageable with an articulating mechanism inthe loading unit to effect articulation of the first and second jawsfrom a linear position to a position angled with respect to alongitudinal axis of the elongated member. The power pack can include asecond motor and the second motor can effect linear movement of thearticulating mechanism.

In some embodiments, the loading unit is removable and replaceable,while the surgical fastener applier remains in a body of a patient, witha second loading unit having a different structure than the loading unitremoved from the surgical fastener applier.

In some embodiments, the loading unit is removable from the surgicalfastener applier without removing the surgical fastener applier from thebody and a second loading unit having fresh fasteners is loadable intothe surgical fastener applier without removing the surgical fastenerapplier from the body.

In accordance with another aspect of the present disclosure, a loadingunit removably loadable into a surgical instrument positioned within abody of a patient is provided. The loading unit includes an elongatedmember, first and second jaws at a distal portion and a firing mechanismmovable within the elongated member to effect firing of fasteners intotissue clamped between the first and second jaws. The loading unit isinsertable into a proximal opening of the surgical instrument andthrough a lumen in a housing and shaft of the instrument while theinstrument is positioned in the body of the patient so the first andsecond jaws extend distally of the shaft of the instrument, the loadingunit actuable by the instrument.

The loading unit can be removable from the surgical instrument withoutremoving the surgical instrument from the body. In some embodiments, theloading unit includes a cartridge containing the fasteners and thecartridge is removable from the loading unit after firing andreplaceable with another cartridge having fasteners. In someembodiments, the loading unit has an articulation member movable withinthe elongated member to move the first and second jaws to an angle to alongitudinal axis of the elongated member.

In accordance with another aspect of the present disclosure, a methodfor reloading a surgical fastener applier is provided comprising thesteps of:

-   -   a) with the surgical fastener applier maintained in a body of a        patient, withdrawing a first loading unit in a proximal        direction through a proximal opening in the surgical fastener        applier, the loading unit having an elongated member, first and        second jaws at a distal portion and a firing mechanism movable        within the elongated member to effect firing of fasteners into        tissue clamped between the first and second jaws; and    -   b) with the surgical fastener applier maintained in the body of        the patient, inserting a second loading unit in a distal        direction through the proximal opening in the surgical fastener        applier, the second loading unit having an elongated member,        first and second jaws at a distal portion and a firing mechanism        movable within the elongated member to effect firing of        fasteners into the tissue clamped between the first and second        jaws.

In some embodiments, the second loading unit operatively connects to anactuator within the surgical fastener applier for firing the fasteners.In some embodiments, the actuator is powered by a motor, the motorcontained in a power pack removably mounted in the surgical fastenerapplier. In some embodiments, the second loading unit includes anarticulation mechanism and the articulation mechanism is engageable witha second actuator within the surgical fastener applier. The secondactuator can be powered by a motor, the motor contained in a power packremovably mounted in the surgical fastener applier.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the subjectinvention appertains will more readily understand how to make and usethe surgical apparatus disclosed herein, preferred embodiments thereofwill be described in detail hereinbelow with reference to the drawings,wherein:

FIG. 1A is a perspective view of a first embodiment of the surgicalstapler (fastener applier) of the present disclosure having a proximalloaded loading unit;

FIG. 1B is a top view of the surgical stapler of FIG. 1A;

FIG. 1C is a side view of the surgical stapler of FIG. 1A;

FIG. 1D is a front view of the surgical stapler of FIG. 1A:

FIG. 2A is a perspective view of the surgical stapler of FIG. 1A showingthe surgical stapler with the power pack prior to insertion into thehandle compartment and further showing the loading unit and the staplecartridge prior to loading;

FIG. 2B is a perspective view of an alternate embodiment of the surgicalstapler of the present disclosure showing the surgical stapler with thepower pack prior to insertion into the handle compartment and furthershowing the loading unit and the staple cartridge prior to loading;

FIG. 3A is perspective view of the loading unit of FIG. 2A;

FIG. 3B is a perspective view of an alternate embodiment of the loadingunit of the present disclosure;

FIG. 4A is a perspective view of the staple cartridge of FIG. 2A;

FIG. 4B is an enlarged view of the area of detail identified in FIG. 4A;

FIG. 5A is perspective view of the loading unit of FIG. 2A with thestaple cartridge not yet loaded into the unit;

FIG. 5B is an enlarged view of the area of detail identified in FIG. 5A;

FIG. 6A is a perspective view of the surgical stapler of FIG. 1A shownextending through tissue;

FIG. 6B is a perspective view similar to FIG. 6A showing the loadingunit prior to being loaded into the surgical stapler positioned intissue;

FIG. 6C is a perspective view showing the surgical stapler connected toa robotic arm and the loading unit shown prior to insertion into thestapler;

FIG. 6D is a perspective view similar to FIG. 6C showing the loadingunit positioned within the stapler;

FIG. 7A is a top view of an alternate embodiment of the stapler of thepresent disclosure;

FIG. 7B is a cross-sectional view taken along line H-H of FIG. 7B;

FIG. 7C is a close up view of the area of detail identified in FIG. 7B;

FIG. 8A is a top view of the motor and drive mechanism (assembly) of thepower pack of FIG. 2B (and FIG. 2A) for firing the staples;

FIG. 8B is a side view of the motor and drive mechanism of FIG. 8A;

FIG. 8C is a top view of the power pack of FIG. 2B;

FIG. 8D is a side view of the motor and drive mechanism of FIG. 8A shownengaged with the rod of the firing assembly of the loading unit of FIG.2A;

FIG. 8E is a perspective view of the motor and drive mechanism of FIG.8A;

FIG. 8F is a cross-sectional view taken along line G-G of FIG. 8Cshowing the power pack engaging the firing rod of the disposable loadingunit of FIG. 2A;

FIG. 9A is a top view of an alternate embodiment of the power pack toeffect both articulation and firing of the surgical stapler;

FIG. 9B is a cross-sectional view taken along line AW-AW of FIG. 9A;

FIG. 9C is a side view of the power pack of FIG. 9A;

FIG. 9D is a cross-sectional view taken along line AT-AT of FIG. 9C;

FIG. 10A is a top view of the motor and drive mechanism (assembly) ofthe power pack of FIG. 9A for effecting articulation;

FIG. 10B is a side view of the motor and drive mechanism of FIG. 10A;

FIG. 10C is a side view of the motor and drive mechanism of FIG. 10Ashown engaged with the articulation rod of the articulation assembly ofthe loading unit;

FIG. 10D is a perspective view of the motor and drive mechanism(assembly) of FIG. 10A;

FIG. 11A is a perspective view of the motor and drive mechanism(assembly) of the power pack of an alternate embodiment having a beltdrive;

FIG. 11B is a top view of the motor and drive mechanism (assembly) ofFIG. 11A;

FIG. 12A is a perspective view of the motor and drive mechanism(assembly) of the power pack of another alternate embodiment having abelt drive;

FIG. 12B is a top view of the motor and drive mechanism of FIG. 12A;

FIG. 13A is a side view of an alternate embodiment of the surgicalinstrument containing the power pack and a proximal loaded disposableloading unit of the present disclosure;

FIG. 13B is a side view of the surgical stapler of FIG. 13A without theloading unit;

FIG. 13C is a side view of the loading unit prior to loading into thesurgical stapler of FIG. 13A;

FIG. 14A is a side view of another alternate embodiment of the surgicalinstrument containing the power pack and a proximal loaded disposableloading unit of the present disclosure;

FIG. 14B is a side view of the surgical stapler of FIG. 14A without aloading unit;

FIG. 14C is a side view of the disposable loading unit prior to loadinginto the surgical stapler of FIG. 14A;

FIG. 15 is a side view of an alternate embodiment of the surgicalstapler having manual firing;

FIG. 16 is a perspective view showing one embodiment of a kit of thepresent disclosure having two loading units containing different jawassemblies;

FIGS. 17A, 17B, 17C, 17D, and 17E are perspective views of various jawassemblies of the loading units of the present disclosure; and

FIG. 17F is a perspective view of a distal end of a loading unit havinga tracker for applying tacks to tissue.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present disclosure provides disposable loading units which can beloaded into surgical instruments without removing the instruments fromthe body. That is, the loading units are loaded through a proximalopening in the surgical instrument and are engageable with an actuatorof the surgical instrument to effect operation of the loading unit. Inembodiments disclosed herein, the loading unit is loaded into a surgicalfastener applier to apply fasteners to tissue clamped between the jawsof the loading unit. However, it is also contemplated that other loadingunits performing other functions can be loaded into the surgicalinstrument in situ. By enabling removal and reloading without removingthe instrument from the body, the user does not need to relocate theinstrument for each use, e.g., for each firing, which would otherwise berequired if the instrument is removed from the surgical site, andreloaded outside the body of the patient. The present disclosure alsoprovides instruments for receiving the loading units and a method forloading the loading units which are described in detail below.

In some embodiments, instead of manual actuation of fastener firingand/or articulation, the loading unit actuation is effected by a batteryand power train, which are loadable into a surgical fastener applier(stapler) to power various functions of the loading unit to reduce theforces exerted by the clinician otherwise required if manual force wasutilized. The surgical staplers in these embodiments are designed toremovably receive the power pack in a compartment or receptacle and thepower pack interacts with the loading unit to effect firing of thefasteners, e.g. staples. In some instances, the power pack can be usedto effect articulation of the jaw assembly of the loading unit to pivotthe jaw assembly with respect to the longitudinal axis of the stapler.The surgical stapler could alternatively have a non-removable powertrain for effecting firing and/or articulation of the instrument.

The power pack can also be utilized for powering endoscopic linearstaplers, such as the stapler depicted in FIG. 1A, other types ofstaplers as well as other surgical instruments. Examples of theseinstruments are discussed below.

The loading units (magazines) are preferably disposable. The loadingunits can be designed/configured for use with endoscopic linear staplersas well as other types of staplers and other types of surgicalinstruments. Examples of these instruments are also discussed below. Theloading units can be used with surgical instruments which are fullymanually actuated or fully powered, or with surgical instruments whereinsome functions are manually actuated and other functions are powered(e.g., powered by a motor).

When the loading units are used with surgical staplers that dissect andjoin a given length of tissue, they enable multiple use, e.g., multiplefirings, in a single procedure. That is, after the fasteners have beenspent, the loading unit is proximally withdrawn from the stapler forloading of a fresh staple cartridge into the removed loading unit oralternatively a new loading unit with a fresh staple cartridge isprovided. In either case, the loading unit with fresh staples isproximally loaded into the stapler, i.e., inserted through the back endof the handle assembly, without requiring the time consuming andsometimes difficult reinsertion/repositioning of the surgical stapler atthe target site. This reloading of the surgical stapler can be repeatedmultiple times in the surgical procedure. When reloaded, the loadingunit engages the handle assembly of the surgical stapler to interactwith the actuators as described below. Thus, during a laparoscopicprocedure for example, by removing and reloading the loading unitproximally while maintaining the instrument inside the patient'sabdomen, the distal tip of the instrument remains within the field ofview of the laparoscopic camera throughout the procedure.

Referring now to the drawings and particular embodiments of the presentdisclosure, wherein like reference numerals identify similar structuralfeatures of the devices disclosed herein, there are illustrated severalembodiments of the surgical instruments and removable power packs of thepresent disclosure.

FIGS. 1A-2A illustrate one embodiment of an endoscopic linear stapler ofthe present disclosure which is inserted through a trocar (surgicalport) and fires linear rows of surgical staples from a cartridge throughtissue into contact with an anvil which forms the individual staples.(In some embodiments, the staplers can be inserted without a trocar).The stapler in this embodiment includes an open compartment in thehandle housing that enables easy loading of the power pack within thestapler. The stapler could also include a compartment with a cover thanis openable and closable as in the openable compartment disclosed inFIG. 2B. In these versions with the cover, the staplers also provide atight seal to protect the power pack from contaminants so that the powerpack does not need to be sterilized for multiple uses.

The power pack is engageable with a staple drive (staple firing)mechanism of the loading unit so that once the power pack and theloading unit are loaded in the stapler, actuation of the motor withinthe power pack effects firing of the staples through tissue. In someembodiments, the power pack is engageable with an articulation mechanismin the loading unit wherein actuation of the motor effects articulationof the jaw assembly of the loading unit. The powered articulation can bein addition to the powered staple firing or alternatively the staplercould have powered articulation and manual staple firing. A specificembodiment of such powered articulation included with powered firing isshown in FIGS. 9A-10D and discussed in detail below. Note in theembodiments discussed herein, the power pack could be loaded first,followed by insertion of the loading unit or alternatively the loadingunit could be loaded first followed by insertion of the power pack.

In the embodiments utilizing a power pack, the power pack with its motordriven mechanism has the advantages of reducing the force requirementsof the user which can be high when multiple rows of staples are firedeither simultaneously or sequentially from the stapler. The power packin certain embodiments, such as in FIG. 2B, can be held in a sealedcompartment of the stapler, thereby avoiding the need forresterilization and its associated costs and risks, including the riskof damage to the electronic components by heat or chemicals.

The term “surgical fasteners” as used herein encompasses staples havinglegs which are deformed by an anvil, two part fasteners wherein afastener or staple component with legs is received and retained in asecond component (retainer), and other types of fasteners which areadvanced through tissue of a patient in performing surgical procedures.

The term “proximal” as used herein denotes the region closer to the userand the term “distal” as used herein denotes the region further from theuser. The terms “top” or “upper” and “bottom” or “lower” refer to theorientation of the instruments as shown in the orientation of theinstrument in FIG. 2A, with the compartment for receiving the power packbeing on the top and the handle extending at the bottom.

Turning initially to FIGS. 1-2A, a first embodiment of the surgicalstapler, power pack and loading unit are illustrated. In thisembodiment, the power pack, which contains a battery, motor, drivemechanism and stapler engagement structure effects firing of thesurgical fasteners (staples).

The surgical stapler, also referred to herein as the surgical fastenerapplying instrument or surgical fastener applier, is designatedgenerally by reference numeral 10 and includes a proximal portion 14, adistal portion 12 and an elongated or endoscopic portion 16 (alsoreferred to as an elongated tubular portion or shaft) extending betweenthe proximal portion 14 and the distal portion 12. A handle assembly 15with a housing 17 (also referred to herein as a handle housing) ispositioned at the proximal portion 14 and is configured to house andprotect internal mechanisms of the stapler and receive the removablepower pack when loaded (mounted) therein.

The loading unit 50 (also referred to herein as the disposable loadingunit or the magazine) includes an elongated member 51 (also referred toas an endoscopic portion or an elongated tubular member), a handleportion 53 of larger diameter, and a locking knob 55 at a proximal end.At the distal portion are opposing members, i.e., jaws, 52 a, 52 b,configured to clamp and constrain tissue during operation of thesurgical stapler. At least one of the jaws is movable with respect tothe other jaw from an open position to receive tissue between the jawsand a closed position to clamp tissue between the jaws. Thus, one of thejaws can be stationary and the other jaw movable with respect to thestationary jaw or alternatively both jaws can move, e.g., pivot, towardeach other. In the embodiment of FIG. 1A, both jaw 52 b, which containsan anvil with staple forming pockets (staples) and jaw 52 a whichcontains the cartridge supporting the row(s) of surgical fasteners, aremovable toward and away from each other. In alternate embodiments, jaw52 b which contains the anvil pockets is movable with respect tonon-pivoting (stationary) jaw 52 a which contains at least one row ofsurgical fasteners. In other alternate embodiments, the movable jaw 52 bcontains the surgical fasteners and the stationary jaw 52 a contains theanvil pockets. Jaws 52 a, 52 b are collectively referred to herein asjaws 52. The fasteners are fired (advanced) from jaw 52 a by linearmovement of a firing mechanism which engages staple drivers within thejaw 52 a which move transverse to the longitudinal axis, i.e.,transverse to the direction of movement of the firing mechanism, tosequentially advance (from proximal to distal) the staples in the linearrows of staples from the jaw 52 a and through tissue clamped by the jaws52 to engage the anvil pockets on jaw 52 b for formation of the staples.The fasteners can be contained in a separate cartridge 60 which isloaded into jaw 52 a prior to insertion of the loading unit 50 into thesurgical instrument.

The elongated tubular member 16 of stapler 10 extends distally from thehousing 17 and is configured to fit through a surgical port (trocar)used for laparoscopic surgery. The elongated tubular member 16 can be ofvarying dimensions and in some embodiments is configured to fit througha 10 mm trocar, although other dimensions for fitting through other sizetrocars are also contemplated such as trocars ranging from 5 mm to 15mm. It is advantageous to minimize the diameter of the endoscopicportion to minimize the size of the patient's incision. With the jaws 52in the clamped position, the outer diameter of the elongated member 16is maintained as the cross-sectional dimension of the closed jaws 52preferably does not exceed the cross-sectional dimension (i.e.,diameter) of the tubular member 16.

The loading unit 50 is inserted in a distal direction through a proximalopening 23 in the housing 17, through a lumen in the housing 17 andthrough the lumen in elongated member 16, with a portion of shaft 51 andthe jaws 52 exiting the distal opening in the lumen of the elongatedmember 16 so jaws 52 extend distally of the elongated member 16 and areexposed. The loading unit 50 is removable by withdrawing the loadingunit in a proximal direction (with the jaws 52 closed) so it isretracted through the lumen in elongated member 16, the lumen in thehousing 17 and out the proximal opening 23. In the illustratedembodiment, the power pack 30 has a slot or channel 34 to accommodatethe loading unit 50.

The loading unit 50 can in some embodiments include a joint 54 thatprovides for the articulation of the opposing jaw members 52, i.e.,pivoting of the jaw assembly (jaws 52) to angular positions with respectto the longitudinal axis of elongated member 51 of the loading unit so(and thus with respect to the longitudinal axis of shaft 16 of thestapler 10). Articulation can be achieved by linear motion of elongatedmembers extending through the elongated member 51 which are slidable toangle the jaw assembly.

The loading unit has a transverse rod 58 extending from a side of thehandle portion 53 of the loading unit 50 to engage an internal wall ofthe handle assembly. Elongated slot 56 provides an opening for a firstengagement member, e.g., flag, of the power pack 30 to engage the firingmember which is internal of handle 53 and/or for a second engagementmember, e.g., another flag, to engage the articulation member which isinternal of handle 53. The elongated member 51 has a laser cut portion59 proximal of joint 54.

The jaw 52 a of proximally loaded loading unit 50, as noted above andillustrated in FIG. 2A, receives a cartridge 60 containing fasteners,e.g., staples. Thus, after firing, the cartridge 60 can be removed and anew cartridge 60 can be loaded into jaw 52 a containing staples 66,linear rows of slots 62 to receive the linear rows of staples 66,stapler drivers to advance the staples transversely through the slotsand a knife bar 68 (see FIGS. 4A and 4B) advanceable in linear slot 69to cut tissue between the rows of staples 66. In a preferred embodiment,separate cartridges 60 are loaded into the proximal loading unit 50after it is withdrawn proximally from the stapler so a single loadingunit 50 can receive multiple cartridges 60 (see FIGS. 5A and 5B). In analternate embodiment, the proximally loaded loading unit can contain anon-removable cartridge so that a new proximal loading unit with a fresharray of fasteners replaces the loading unit with the fired staples. Ineither embodiment, the loading unit is proximally loaded into thestapler (in a distal direction) and withdrawn proximally from thestapler in situ.

The instrument 10 can include a rotational member or knob 22 engageablewith the loading unit 50 and configured to rotate, with respect to thehandle assembly, the elongated member 51 and connected jaws 52 about theaxis of the elongated member 51, e.g., 360 degree rotation, to changethe position of the jaws 52. Articulation can be effected by manualmanipulation of a lever adjacent the handle assembly 15. A handle lever24, linked to an axially movable clamping bar within the loading unit,is pivotable from a first position to a second position closer tostationary handle 26 to effect movement of the jaw 52 b and jaw 52 afrom an open (unclamped) position to a clamping position, also referredto as a closed position of the jaws 52. Release of handle lever 24returns the jaws 52 b, 52 a to their open position. A locking lever canbe provided to retain the handle 24 in the closed position. Stationaryhandle 28 for grasping by the user is ergonomically designed for comfortof use. In summary, with a loading unit positioned within the stapler10, the surgical stapler 10 operates by manual pivoting of the lever 24toward stationary handle 26, wherein it can be locked by latch 28, toclamp the tissue between jaws 52, followed by powered firing of thestaples from jaw 52 a, through the clamped tissue and into contact withthe staple forming pockets of the anvil of jaw 52 b. Prior to firing,the jaws 52 can be rotated to a desired orientation by rotation ofendoscopic portion 51 of loading unit 50 via knob 22 and/or articulatedabout joint 54, via movement of the elongated articulation members, to adesired angled position with respect to the longitudinal axis ofelongated portion 51 (and shaft 16). Note articulation can performed bymanual manipulation of a lever (not shown) which is operativelyconnected to an internal elongated member within the loading unit 50which extends to joint 54. A force applied to the internal elongatedmember pivots/articulates the jaws 52 about the joint 54. Alternatively,powered articulation can be provided.

The stapler can include a firing lock to maintain the jaws 52 a, 52 b inan actuation position. The firing lock may be engaged by squeezing thelever 24 of the handle assembly, which thus maintains the distal jaws 52a, 52 b in the closed position. Upon completion of tissue joining anddissection, the firing lock may be released by fully squeezing the lever24 to open jaws 52 a, 52 b, for example, through spring loading or thelike.

In some embodiments the loading unit can be inserted into the staplerand then rotated into a loading position. In these embodiments, theloading unit can include a knob with a locking position that provides anindication to a user that the surgical stapler is properly loaded.

The housing 17 of the handle assembly 15 of the surgical stapler 10 isconfigured to receive the loadable/removable power pack 30 in receptacle25. In this embodiment, the power pack housing is not maintained in asterile environment.

In the alternate embodiment of FIG. 2B, the power pack 35 is fullycontained within a compartment 27 b in the handle housing 29 and istherefore maintained in a sterile environment within the surgicalinstrument so it can be removed and reused in another procedure and/orinstrument without the complexities, time, costs and risks ofresterilization of the power pack. The sealed environment of the batteryand power train within the housing also enables certainfeatures/components to be used which might not otherwise be practical ifsterilization of the internal power pack was required. Thus, bypreventing contact between the power pack and the patient and/or bodilyfluids and the external environment, resterilization is not required inthis embodiment.

The receptacle (compartment) 27 b includes a base and side walls 27 chaving one or more guides 27 d that cooperate with corresponding guidingstructures 37 c on the outer wall of the housing 37 a of power pack 35for proper alignment of the power pack 35 in the handle assembly duringinsertion into the receptacle 27 b. In the embodiment of FIG. 2B, theguides 37 c on power pack housing 37 a are in the form of a pair of ribsor projections 37 c extending transversely to a longitudinal axis of thepower pack 35 for receipt within grooves formed between guides, e.g.,ribs or projections, 27 d of the compartment 27 b, also extendingtransversely with respect to a longitudinal axis of the stapler. In theillustrated embodiment, the ribs 37 d are on opposing sides of the powerpack 35 and are axially offset from each other, although in alternateembodiments they can be axially aligned. Additionally, a differentnumber of ribs (axially or non-axially aligned) can be provided (withcorresponding receiving structure in the compartment 27 b). It should beappreciated that alternatively, the grooves could be provided on thepower pack 35 and the ribs provided on the walls in the compartment 27 bto provide the guiding structure for the power pack 35. The guidingstructure also helps to retain power pack 35 in position within thecompartment 27 b. The power pack 35 has rear and front concave regions37 b, 37 d to reduce its overall size. The power pack 35 can include aslot or channel (like slot 34 of power pack 30) to receive/accommodatethe loading unit 50 so it can be inserted through the proximal openingand endoscopic portion 16′ of the stapler. The loading unit 50 isinserted through the proximal opening 29 a of the housing 29.

The handle assembly of the stapler includes handles 24′ and 26′,identical to handles 24, 26 of FIG. 2A, and a rotatable knob 22′identical to knob 22 of FIG. 2A.

A cover 27 a for opening and closing the receptacle 27 b can beprovided. The compartment cover 27 a is shown as being hingedly attachedto the housing 25, but may alternatively be fully removable or attachedin some other manner such as a slidable connection or the like. Thecover 27 a is shown pivotably mounted to a top portion of the housing 29(in the orientation of FIG. 2D) for top loading of the power pack,although alternatively, side or bottom loading can be provided. Thecover 27 a pivots from a closed position to an open position of FIG. 2Bto enable loading of power pack 35 into the compartment 27 a of thehousing 29. In some embodiments, the cover 27 a is spring loaded to anopen position so it remains open for loading of the power pack 35. Onceloaded, the cover 27 a is pivoted about its hinge to its closedposition. A latch can be provided to latch the cover 27 a to the housing29 in the closed position. When the cover 27 a is in an open position,the power pack 35 may be removed from the receptacle 27 b or insertedinto the receptacle 27 b.

In some embodiments, when the cover 27 a is in a closed position, theseal of the cover 27 a is in contact with the rim of the housing 29 suchthat the receptacle 27 b, and the power pack 35 if inserted into thereceptacle 27 b, is sealed from the environment exterior to the surgicalstapler. The top seal can be attached to the cover 27 a and in someembodiments can be in the form of an elastomer that is compressed by thehousing, e.g., tightly fits slightly within the housing or is pressed onthe rim of the housing 29. In other embodiments, the elastomer seal canbe on the housing 29, i.e., extending around the perimeter of the rim ofthe compartment 27 b, and is compressed by the cover 27 a to sealbetween the cover 27 a and housing 29. Other seals can also be providedwithin the surgical stapler to seal/protect the power pack 35 fromcontaminants, e.g., body fluids. After applications of fasteners andrelease (unclamping of the jaws from tissue), the cover 27 a can beopened and the power pack 35 removed and charged while the stapler andhandle assembly are resterilized if the stapler is a reusable instrumentor the stapler and handle assembly are disposed of if the stapler is asingle use disposable instrument. The power pack 35, due to its sealedconfiguration discussed above, can be reused without requiringsterilization by insertion into the receptacle of a resterilized handleassembly or a sterile handle assembly of an unused disposable handleassembly.

The power packs 30 and 35 can be used with surgical instrumentsdiscarded after use (fully disposable instruments), partially disposablesurgical instruments or with fully reusable/sterilizable instruments.The power packs are easily loadable in the surgical instrument,preferably the handle assembly or housing of the instrument, to easilyand securely engage structure in the loading unit to effect movement ofsuch structure. The power packs are also easily disengageable from thestructure for removal from the housing. The power packs can beconfigured so they can be loadable and engageable in various types ofsurgical instruments.

Turning now to the internal components of the power pack 35 of thepresent disclosure, and with reference to FIGS. 8A-8G, one embodiment ofthe power pack 35 is shown which includes a motor assembly, battery andelectronics contained within housing 35 a. (Power pack 30 contains thesame components and arrangement as power pack 35) More specifically, thepower pack 35 includes a powering assembly including a motor 32connected to a planetary gear box 34 configured to gear down the outputof the motor 32 for proper drive speeds for firing staples from jaw 52 athrough the tissue into contact with the anvil of jaw 52 b. Theplanetary gear box 34 drives a lead screw 36 through one or more gearsoperatively connected to the motor shaft. More specifically, uponrotation of the motor shaft by motor 32 in a first direction, gear 38 isrotated in the same first direction, causing rotation of the gear 31 ina second opposite direction due to the intermeshed teeth of gears 31 and38. Lead screw 36 is operatively connected to gear 31 so that rotationof gear 31 causes rotation of lead screw 36 in the same direction. Thepower pack 35 includes a battery 33 which can be rechargeable outsidethe stapler when the power pack 35 is removed. The power pack 35 in someembodiments can include a power switch which is activated, i.e., turnedon, by the clinician to start the motor and effect staple firing. Inother embodiments, the motor can automatically turn on when the powerpack is fully loaded or upon actuation of another control on the staplerhousing 17. In some embodiments, the motor can automatically turn offwhen the power pack is removed from the stapler housing. Note the powerpack 35 has a different housing configuration than power pack 30 of FIG.2A. However, the internal mechanisms are the same.

Connected to the end of lead screw 36 (the end opposite the connectionto the gear 31) is a drive mechanism 40. The drive mechanism 40 isconfigured to move in a linear motion (in an axial direction) along thelead screw 36 in response to rotation of the lead screw 36. For example,the drive mechanism 40 may include internal threads that engage externalthreads of the lead screw 36 and may include slides engaged in a trackthat prevent the drive mechanism 40 from rotating and therefore causethe drive mechanism 40 to move linearly (axially) in response torotation of the lead screw 36. As depicted in FIGS. 8A-8F, the powerpack 35 has a compact configuration as the lead screw 36 extendsalongside, slightly spaced from, the motor 32 and gear box 34, i.e.,both the motor 32/gear box 34 and lead screw 36 extending longitudinallywith the lead screw 36 parallel to the motor 32. The drive mechanism 40is connected to a proximal end of lead screw 36 and extends proximallyof the proximal end of the motor 32 in the illustrated embodiment.

The power pack 35 can have features/structure to constrain the motor 32.In the embodiment of FIG. 8F, such feature is in the form of proximalrails 70 a and distal rails 70 b spaced apart axially within the housing17. Motor 32 is seated within proximal rails 70 a and gear box 34 isseated within rails 70 b, the rails 70 a, 70 b retaining the motor andpreventing axial and rotational movement within the housing 17. Bearingor bushings 71 a and 71 b can also be provided to constrain the leadscrew 36 at opposing ends, while allowing rotation thereof, thereby alsoconstraining the motor. Other features can additionally or alternativelybe provided to restrain the motor from axial movement while allowingrotation of the lead screw.

The drive mechanism 40 includes a first output flag or yoke 42, which isdiscussed in more detail below, configured to engage a staple firingmechanism, e.g., firing rod 46, extending longitudinally within thedisposable loading unit 50. The staple firing rod 46 extends through theelongated portion 51 of the disposable loading unit 50 and isoperatively engageable with a firing rod which is engageable with aseries of staple drivers in jaw 52 a to advance the fasteners (staples)66 from the fastener jaw 52 a. Alternatively, the firing rod 46 canextend through the elongated portion 51 and itself engage the staplerdrivers as the camming surface of the firing rod 46 engages the stapledrivers to sequentially fire the staples as the firing rod 46 isadvanced. Thus, as the motor 32 generates rotational motion of the leadscrew 36 through the planetary gear box 34 and the gears 38, 30, thedrive mechanism 40 moves in linear motion along the lead screw 36. Suchlinear motion effects linear movement of the firing rod 46 (due to theengagement of the boss 44 by the flag 42) which advances the stapledriving mechanism to advance (fire) the staples out from jaw 52 athrough tissue and into contact with the anvil in jaw 52 b. As notedabove, the firing rod 46 can be a single element extending through theelongated portion 51 (terminating adjacent jaw 52 a) or alternativelycan be attached to one or more components intermediate the firing rod 46and jaw 52 a.

A clamp bar can be positioned within and concentric with firing rod 46.The clamp bar can be operatively connected to the pivotable handle 24 ofstapler 10 via a linkage connecting one end of handle 24 to the distalend of clamp bar. In this manner, movement of pivotable handle 24 towardstationary handle 28 causes the operatively connected jaw clampingmechanism, e.g., the clamp rod, to be advanced distally to pivot jaw 52b toward jaw 52 a to clamp tissue between the two jaws 52. Note that forclamping, the clamp bar slides linearly within a lumen of firing rod 46;for staple firing, firing rod 46 moves linearly over the clamp bar.

The power pack 30 or 35 can also include in some embodiments one or moresensors to indicate the position of the firing rod 46 to indicate to theclinician the status of staple firing. For example, a proximal sensorand a distal sensor can be provided in the power pack housing to sensethe position of yoke 42 of the drive mechanism 40. Thus, the proximalsensor would sense the initial position of the yoke 42 (and thus theinitial position of the firing rod 46) and at the end of the firingstroke, the distal sensor would indicate the end (final) position of theyoke 42 (and thus the final position of the firing rod 46) which wouldindicate completed firing of the fasteners. The power pack 30 or 35could also include an audible or visual indicator (viewable though thepower pack housing and instrument handle housing) actuated by the sensorto indicate to the clinician the position of the flag 42 and thus thecompletion or status of the firing stroke to fire the fasteners. Thepower pack can also include sensors to detect the position of thearticulation flag in the embodiments discussed below which have poweredarticulation. The sensor can include a potentiometer to determine thelocation during the firing stroke. It can also include an encoder todetect the position along the stroke. Alternatively, the stroke can alsobe identified by motor count.

It is also contemplated that in alternate embodiments, the sensor(s) canbe carried by the handle housing and/or the loading unit rather than (orin addition to) the power pack and utilized to detect the position ofthe flag 42 and/or firing rod 46 and/or detect the position of thearticulation flag and/or articulation rod in the embodiments discussedbelow which have powered articulation.

It is also contemplated that a sensor(s) can be provided to detect theposition of the clamping rod for clamping the jaws. The sensor can beprovided in (or supported by) the power pack or alternatively thesensor(s) can be carried by the loading unit and/or by the handlehousing rather than (or in addition to) the power pack and utilized todetect the position of the jaws by detecting the position of the flagengaging the jaw clamping rod and/or detecting the position of the jawclamping rod in the embodiments which have powered clamping.

Note the sensor can be provided in some embodiments; in otherembodiments, no sensor is provided.

The output flag 42 of power pack 18, as shown in FIG. 8D, is configuredto engage a bossed end 44 of the firing rod 46 of the loading unit 50when the power pack 18 is fully inserted into the receptacle 27 b of thehandle assembly 17. As shown, the output flag (yoke) 42 has a receivingor mounting feature or member (also referred to as the engagementfeature (member) or firing rod engagement feature (member) in the formof two arms 43 a and a slot 43 b therebetween, configured tofrictionally (and releasably) engage the bossed end 44, the featurealigning with the bossed end 44 during insertion. (The aforedescribedguiding structure on the power pack 35 and internal wall of thecompartment 27 b aid such alignment). Note the firing rod 46 is able torotate when the first output flag 42 of the power pack 35 is engagedwith the bossed end 44. When the power pack 35 is secured to the firingrod 46 by the first output flag 42, linear motion generated at the firstoutput flag 42 by the motor actuated drive assembly is transferred tothe firing rod 46, which moves linearly to actuate the staple firingmechanism. That is, rotation of the gear 30 effects axial (linear)movement of the drive screw 36 which effects axial (linear) movement ofthe connected drive mechanism 40 to effect axial (linear) movement ofthe associated drive mechanism (rod) engaging member (i.e., flag 42). Itshould be appreciated that flag 42 provides one example of thereleasable attachment (engagement member) of the motor assembly to thefiring rod 46, it being understood that other mounting (engagement)members or features are also contemplated to engage the firing rod toadvance it axially.

In the alternate embodiment of FIGS. 7A-7C, the bossed end 44′, when theloading unit 50 is sufficiently inserted into the stapler, engages edge49 of output flag 42′ (which is identical in structure and function tooutput flag 42 except for the angled edge 49), which biases the bossedend 44′ downwardly to compress spring 19 within the handle housing ofthe stapler. After boss 44 a passes edge 49 and is aligned with therecess/slot in the flag 42, it is biased upwardly (in the orientation ofFIG. 7C) toward the recess/slot by the spring 19 for engagement by theflag 42′ as shown in FIG. 7C so the firing rod of the loading unit isengaged with the drive mechanism of the power pack. Note, in thisembodiment, the bossed end 44′ is a separate piece attached to rod 46′which effects firing in the same manner as rod 46. In an alternateembodiment, the bossed end 44′ and rod 46′ can be one piece. In allother respects, the stapler 10′ of FIG. 7A is the same as stapler 10 ofFIG. 1A and corresponding parts (which have the same structures andfunctions) have been labeled with “prime” designations for convenience.

In the embodiment of FIGS. 1-8F, the proximal loading unit 50 is usedwith a stapler 10 receiving a power pack 35 that actuates the firing rod46 to fire the staples while other steps are performed manually. Insummary, in this embodiment, in use, the jaws 52 a, 52 b are moved tothe closed (clamped) position manually by a hand actuated lever orcontrol, e.g., handle 24. Also, in this embodiment, the jaws 52 arearticulated with respect to the longitudinal axis of the endoscopicportion manually by a hand actuated lever or control. Thus, theclinician would manually clamp the jaws, manually rotate the endoscopicportion and attached jaws 52, and manually articulate the jaws bymanipulation of controls at the proximal end of the stapler 10, e.g., atthe handle 15.

It is also contemplated that the proximal loading unit can be used witha stapler wherein all or some of the steps/functions are manuallyactuated, i.e., clamping, articulation, and firing. An example of thisis shown in FIG. 15. Stapler 220 has a pawl 224 within the handlehousing 222. Loading unit 230 includes an engagement member 232 having arack 234 engageable with the pawl 224. Engagement member 232 isoperatively connected to deployment/firing rod 236 at connection 235.When handle 226 is moved toward handle 228, due to the pawl/rackengagement at connection 235, the engagement member 232 moves distallythereby causing the deployment (firing) rod 236 to move distally to firethe fasteners in the same manner as rod 46 described above. Stapler 220can include a rotation knob 223 which functions like knob 22. Theloading unit 230 in all other respects is identical to the loading unit50 and like loading unit 50 has a pair of jaws for clamping tissue withone jaw receiving the fasteners and an opposing jaw having an anvil. Theloading unit can also provide for articulation of the jaws as in theaforedescribed embodiments. Note the stapler 220 of FIG. 15 can be usedto manually actuate loading units having other configurations such asthe alternate loading units and alternate jaw assemblies disclosedherein.

In some embodiments, the seal inside the tubular member, e.g., tubularmember 16, of the surgical stapler maintains positive pressure so thatthe loading unit may be removed and reloaded during use. The seal maybe, for example, a silicone seal or the like. Additionally, since theseal maintains positive pressure, the tubular member of the surgicalstapler may, advantageously, itself function in certain instances as atrocar for use with other surgical tools.

In some embodiments, the handle lever 24 may have a mechanismoperatively connected thereto that interacts with the loading unit 50 toprevent the lever 24 from being actuated, for example, by squeezing by auser, if the loading unit is not properly loaded into the surgicalstapler. Additionally, in some embodiments, a user will advantageouslybe able to determine if the loading unit 50 is properly loaded into thesurgical stapler via an alignment feature on the knob 55 of the loadingunit 50 configured to indicate proper loading of the loading unit aftersufficient insertion through the proximal entry opening 23 of thestapler such that the knob 55 enters a locking position. The lockingmechanism may be configured to generate an indication to a user when theloading unit is in the locking position, such as an audible sound,tactile feedback, or the like, thereby indicating to a user that thesurgical stapler is properly loaded. For instance, the loading unit 50may be pushed against a spring force generated by a mechanism in thesurgical stapler. (Note that the mechanism of FIG. 7C described hereincould provide such audible or tactile feedback due to the spring action)Once in the locking position, the loading unit 50 can be retained untilthe locking mechanism is engaged to release the loading unit.

FIG. 1A shows one embodiment, of an endoscopic linear stapler that canhave proximal loaded loading unit of the present disclosure, and FIGS.6A and 6B show the endoscopic linear stapler extending through a trocarT passing through tissue A. (FIG. 6B shows loading unit 50 prior toinsertion in a distal direction through the handle and endoscopicportion 16 of the stapler 10). However, the loading unit of the presentdisclosure is not limited to such endoscopic linear staplers. Forexample, FIGS. 14A-14C illustrate another endoscopic linear stapler,designated by reference numeral 120, that can utilize the loading unitof the present disclosure. The stapler 120 can be manually actuated orcan receive and be powered by the power pack 30 or 35. Stapler 120 has ahandle 132 manually pivotable towards stationary handle 130 for clampingof the jaws, an endoscopic portion or shaft 124 extending from thehandle housing 128, and a loading unit 121 with a jaw assemblycontaining jaws 122 a, 122 b at a distal portion of elongated member125. The endoscopic portion 124 is flexible which enables use in variousendoscopic procedures. In some embodiments, the flexible endoscopicportion 124 can be stretched to make it more rigid to facilitateinsertion of the loading unit 121 through the lumen in the endoscopicportion 124. The stapler 120 also includes a rotation knob 126 forrotation of the elongated portion 123 of loading unit 121 to rotate thejaws 122 a, 122 b. Power pack 35 is shown fully loaded (inserted) withinthe handle housing 128 and the cover 129 closed to seal the power pack35 from the external environment. As in the embodiment of FIGS. 8E-8F,the flag 42 extending from lead screw 36 engages a firing rod within theelongated member 125 of loading unit 121 to effect movement of theflexible firing rod to fire the staples when the motor of the power pack35 is actuated. Power pack 90 having articulation described below canalso be utilized with stapler 120. Manual firing and/or manualarticulation rather than powered are also contemplated.

In use, the loading unit 121 is inserted in a distal direction through aproximal opening in the stapler and through a lumen in the handlehousing 128 to extend through the lumen in endoscopic portion 124. Asnoted above, the endoscopic portion can be stiffened prior to insertionof the loading unit 121 so it assumes a more linear position tofacilitate insertion of the loading unit 121. (The loading unit 121could also be stiffened prior to insertion if it is provided with aflexible elongated member). The power pack 35 engages the loading unit121 in a similar manner as engagement with loading unit 50. As withloading unit 50, after staple firing, the loading unit 121 can beremoved by proximal withdrawal (retraction) through the endoscopicportion 124 and through the handle housing 128 and proximal opening forreplacement with another loading unit with fresh staples, or replacementof the same loading unit with a fresh cartridge, for proximal loadinginto the stapler 120. As noted above, the insertion (loading) andreloading with fresh staples can be achieved while the instrumentremains in position, i.e., without moving the instrument from itslocation in the body and/or without withdrawing the instrument from thepatient.

The loading unit is also not limited to use with endoscopic linearstaplers, nor is it limited to use with staplers. FIGS. 13A and 13Billustrate one example of a different stapler with a proximally loadedloading unit. As in the endoscopic linear staplers discussed herein,these staplers can also have a knife bar to cut tissue between the rowsof staples applied to the tissue.

By way of example, a proximal loaded loading unit can be used with acircular stapler that applies circular arrays of staples such as shownin FIGS. 13A-13C. Surgical stapling instrument 100 can be manuallypowered or can receive and be powered by the power pack 35 or 30 of thepresent disclosure. Stapler 100 has a handle 117 manually pivotabletowards stationary handle 118 for clamping of the jaws, an elongatedtubular portion or shaft 112 extending from the handle housing 116 and adisposable loading 101 with a jaw assembly having an anvil (jaw) 102 anda cartridge (jaw) 106 containing circular arrays of fasteners (staples).The anvil 102 has a proximal clamping surface 108 and is movable byanvil rod 104 toward the cartridge 106 to clamp tissue between the anvilclamping surface 108 and distal clamping surface 110 of cartridge 106 bymanual movement of handle 117 toward stationary handle 118. The stapler100 also includes a rotation knob 114 for rotation of the elongatedportion (shaft) 105 of the loading unit 101 to rotate the jaws 102, 106.Power pack 35 is shown fully loaded (inserted) within the handle housing116 and the cover is shown closed to seal the power pack 35 from theexternal environment. As in the embodiment of FIGS. 8A-8F, the flag 42extending from lead screw 36 engages a firing rod within the loadingunit 101 to effect movement of a firing rod extending through elongatedportion 105 to fire the circular arrays of staples when the motor of thepower pack 35 (or 30) is actuated. Power pack 90 having articulationdescribed below can also be utilized with stapler 100. Manual firingand/or articulation is also contemplated. In use, the loading unit 101is inserted through a proximal opening in the stapler 100 and through alumen in the handle housing to extend through the lumen in elongatedportion 112. As with loading unit 50, after staple firing, the loadingunit 101 can be removed by proximal withdrawal (retraction) through theelongated portion 112, the handle housing 116 and the proximal openingfor replacement with another loading unit with fresh staples, orreplacement of the same loading unit with a fresh cartridge and in someembodiments a fresh anvil, for proximal loading (in a distal direction)into the stapler 100. As noted above, the insertion (loading) andreloading can be achieved while the instrument remains in position,i.e., without moving the instrument from its location in the body and/orwithout withdrawing the instrument from the patient. The anvil 102 canbe tiltable as it is inserted through the housing 116 and elongatedportion 112 to facilitate insertion. The cartridge 106 can also betiltable for insertion. The anvil 102 and/or cartridge 106 canalternatively or in addition be collapsible and expandable to facilitateinsertion through the elongated portion 112.

In the embodiments of FIGS. 8A-8F, a gear mechanism is driven by themotor to rotate the lead screw to advance the drive mechanism to effectfiring of the staples. In the alternate embodiments of FIGS. 11A-12B, abelt drive mechanism is used to effect firing. The belt drive mechanismis contained in the power pack 35 or 30 (or 90) in the same manner asthe gear mechanism of the foregoing embodiments, and thus the power packfor the belt drive would include the housing 35 a of the configurationof FIG. 2B or housing 31 of the configuration of FIG. 2A and loaded inthe stapler in the same manner as the power packs described above. Thebelt drives of FIGS. 11A-12B are described below for use with thestapler of FIG. 1A but can be used in the other surgical staplers andinstruments disclosed herein which are designed to receive power pack30, 35 or power pack 90 for powered actuation.

Turning first to the embodiment of FIGS. 11A-11B, the belt driveassembly (mechanism) includes a motor 148 connected to a planetary gearbox 150 configured to gear down the output of the motor 148 for properdrive speeds for firing staples from jaw 52 a through the tissue intocontact with the anvil of jaw 52 b. The planetary gear box 150 drives alead screw 144 via the drive belt operatively connected to the motorshaft. More specifically, upon rotation of the motor shaft by motor 148,first rotatable disc 152 (also referred to as the first wheel or pulley)is rotated in a first direction, causing movement of belt 156 androtation of second rotatable disc 154 (also referred to as the secondwheel or pulley). Note the two discs 152, 154 are spaced apart and notin contact. Lead screw 144 is operatively connected to disc 154 so thatrotation of disc 154 causes rotation of lead screw 144 in the samedirection. The power pack 35 (or 30) includes a battery which can berechargeable outside the stapler when the power pack 35 is removed. Themotor 148 is actuated in the various ways described above with regard topower pack 35 of FIG. 8C. A tensioner can be provided such as tensioner158, illustratively in the form of a tension disc or wheel, to apply aforce against the belt 156. In the orientation of FIG. 11A, thetensioner 158 is positioned underneath the drive belt 156 and applies anupward tensioning force against the belt 156 in a direction toward discs152, 154. Other types of mechanisms to apply a tensioning force to thebelt are also contemplated for use in the embodiments of FIGS. 11A-12Bif such tensioning of the drive belt 156 is desired.

Connected to the end of lead screw 144 (the end opposite of theconnection to the disc 154) is a drive mechanism 142. The drivemechanism 142, like drive mechanism 40 of FIG. 8A, is configured to movein a linear motion (in an axial direction) along the lead screw 144 inresponse to rotation of the lead screw 144. For example, as in the drivemechanism 40, drive mechanism 142 may include internal threads thatengage external threads of the lead screw 144 and may include slidesengaged in a track that prevent the drive mechanism 142 from rotatingand therefore cause the drive mechanism 142 to move linearly in responseto rotation of the lead screw 144. As shown, the lead screw 144 extendsalongside, slightly spaced from, the motor 148 and gear box 150, i.e.,both the motor 148/gear box 150 and lead screw 144 extendinglongitudinally with the lead screw 144 parallel to the motor 148. Thedrive mechanism 142 extends proximally of the proximal end of the motor148 in the illustrated embodiment.

The drive mechanism 142, like drive mechanism 140 of FIG. 8E, includes afirst output flag or yoke 146 with slot 143 configured to engage astaple firing rod 46 of the loading unit 50 extending longitudinallywithin the handle 4. The flag 146 is the same as flag 42 of FIG. 8E andengages the staple firing rod 46 in the same manner as flag 42.Therefore, for brevity, further discussion of flag 146 and it engagementwith firing rod 46 is not provided as the structure and function of flag42, and alternative firing rod engagement features, are fully applicableto flag 146 of FIGS. 11A-11B. In brief, as the motor 148 generatesrotational motion of the lead screw 144 through the drive belt, thedrive mechanism 144 moves in linear motion along the lead screw 144 toeffect linear movement of the firing rod 46 which advances the stapledriving mechanism to advance (fire) the staples out from jaw 52 athrough tissue and into contact with the anvil in jaw 52 b.

In an alternate embodiment of a belt drive mechanism, the belt drivemechanism can have different sized discs (wheels). That is, one discwhich is operatively connected to lead screw 144 is larger in diameterthan other disc. Consequently, instead of providing a one to one ratioof the discs as in discs 154 and 152 of FIG. 11A, a greater ratio ofdisc to disc is provided which varies the output of motor 168. That is,the rotational output of lead screw 144 is less than the rotationaloutput of the motor shaft due to the differing degree of rotation due tothe varying sizes. An example of such different sized discs is shownwith the alternate belt drive mechanism of FIGS. 12A and 12B.

FIGS. 12A-12B illustrate an alternate embodiment of a belt drivemechanism. The belt drive 200 differs from the belt drive of FIG. 11A inthat discs 212, 214 have teeth to engage ribs or treads on belt 216. Asshown, the toothed discs 212, 214 are spaced apart so theirteeth/projections do not intermesh—the teeth of disc 212 engage belt 216and the teeth of disc 214 engage belt 216. Rotation of disc 212 movesdrive belt 216 in the same direction due to its engagement with theteeth, which causes rotation of toothed disc 214 in the same directiondue to engagement with its teeth to rotate lead screw 204. In all otherrespects, mechanism 200 is identical to mechanism 140.

Belt drive mechanism (assembly) 200 has a motor 208 connected to aplanetary gear box 210 configured to gear down the output of the motor208. The planetary gear box 210 drives a lead screw 204 through the beltdrive operatively connected to the motor shaft. Upon rotation of themotor shaft by motor 208, first disc (wheel or pulley) 212 is rotated ina first direction, causing movement of belt 216 and rotation of seconddisc (wheel or pulley) 214. Lead screw 204 is operatively connected todisc 214 so that rotation of disc 214 causes rotation of lead screw 204in the same direction. A tensioner 218 like tensioner 158 can beprovided to apply tension to the belt 216. The drive mechanism 202, likethe drive mechanism 142 of FIG. 11B, includes a first output flag oryoke 206 with slot 203 configured to engage a staple firing rod 46 ofthe proximal loading unit in the same manner as flag 42. Rotation of themotor shaft generates rotational motion of the lead screw 204 throughthe drive belt, causing the drive mechanism 202 to move in linear motionalong the lead screw 204 to effect linear movement of the firing rod 46which advances the staple driving mechanism to advance (fire) thestaples out from jaw 52 a through tissue and into contact with the anvilin jaw 52 b.

The second toothed disc 214 which is operatively connected to lead screw204 is larger in diameter than first toothed disc 2122. Consequently,instead of providing a one to one ratio of the discs as in discs 154,152, a greater ratio of disc 214 to disc 212 is provided which variesthe output of motor 208. That is, the rotational output of lead screw204 is less than the rotational output of the motor shaft due to thediffering degree of rotation of discs 214, 212 due to the varying sizes.It should be appreciated that in alternative embodiments, the tootheddiscs 212 214 can be the same size as in the embodiment of FIG. 11A.

It should be appreciated that the foregoing belt drive mechanisms can beused as an alternative to the gear mechanism in power pack 30 or 35 aswell as an alternative to one or both of the gear mechanisms of powerpack 90 discussed herein.

In the foregoing embodiments, the power packs 30 and 35 were describedfor powering staple firing. In an alternate embodiment, the power packcan include a drive mechanism for effecting articulation. This motorpowered articulation can be in addition to the motor powered staplefiring, or alternatively, the power pack can be used solely for poweredarticulation. The embodiment of FIGS. 9A-10D illustrate a power packwhich powers both staple firing and articulation. If only forarticulation, the power pack described herein (power pack 90) would notinclude the gear mechanism engageable with the firing rod 46 for staplefiring.

The power pack 90 can be loaded in the staplers disclosed herein in thesame manner as power pack 35 and 30, however, the engagement features ofthe power pack 90 engage both the firing rod of the loading unit, e.g.,loading unit 50, as well as the articulation rod of the loading unit. Inthe illustrated embodiment, the power pack 90 is shaped like power pack35 and can have guides e.g., projections 90 a, 90 b, either axiallyaligned or axially offset, similar to guides 37 c of power pack 35 foralignment with guiding structure in the compartment of the stapler

More specifically, the power pack has a motor assembly and drivemechanism for firing staples which is identical to that of the powerpack 35 of FIG. 2B. However, power pack 90 differs from power pack 35(and power pack 30) in that it additionally has a motor assembly anddrive mechanism for articulating the jaws of the loading unit. Theaddition of the articulation assembly can be appreciated by a comparisonof the cross-sectional view of FIG. 8F, which only effects firing of thefasteners (staplers), and the cross-sectional view of FIG. 9D whicheffects firing of fasteners and articulation of the jaw assembly.

The powered staple firing assembly like the firing assembly of powerpack 35 of FIG. 8F, includes a motor 83 connected to a planetary gearbox 85 configured to gear down the output of the motor in the samemanner as motor 32 and gear box 34 of power pack 35. The planetary gearbox 85 drives a lead screw 86 through one or more gears operativelyconnected to the motor shaft. Upon rotation of the motor shaft by themotor 83 in a first direction, gear 81 is rotated in the same firstdirection, causing rotation of the gear 84 in a second oppositedirection due to the intermeshed teeth of gears 81 and 84. Lead screw 86is operatively connected to gear 84 so that rotation of gear 84 causesrotation of lead screw 86 in the same direction. The power pack 90includes a battery 33 which can be rechargeable outside the stapler whenthe power pack 90 is removed. The power pack 90 in some embodiments caninclude a power switch which is activated, i.e., turned on, by theclinician to start the motor and effect staple firing. In otherembodiments, the motor can automatically turn on when fully loaded orupon actuation of another control on the stapler housing.

Connected to the end of lead screw 86 (the end opposite the connectionto the gear 84) is a drive mechanism 80 which is configured to move in alinear motion (in an axial direction) along the lead screw 86 inresponse to rotation of the lead screw 86. Drive mechanism 80 includes aflag or yoke identical to yoke 42 of power pack 35 discussed above,which engages the flange or boss 44 of firing rod 46 within the loadingunit. The connection of the flag to the firing rod, the motor and gearmechanism, and the drive mechanism 80 of power pack 90 are the same asthe power pack 35 and therefore the aforedescribed functions andfeatures/components of power pack 35 for staple firing are fullyapplicable to the function and features/components of power pack 90 forstaple firing so for brevity are not fully repeated herein. It shouldalso be appreciated that the alternative mechanisms for motor poweredstapled firing, such as the various belt drive mechanisms discussedabove and/or illustrated in the Figures, can also be used in the powerpack 90 to effect staple firing. Additionally, the various sensorsdiscussed above with regard to sensing the firing stroke can also beprovided in power pack 90 for the same uses.

Power pack 90 also has an articulation assembly that includes a poweringassembly including a motor 96 connected to a planetary gear box 93configured to gear down the output of the motor 96. The planetary gearbox 93 drives a lead screw 98 through gears 91, 92 operatively connectedto the motor shaft. More specifically, upon rotation of the motor shaftby motor 96 in a first direction, gear 91 is rotated in the same firstdirection, causing rotation of the gear 92 in a second oppositedirection due to the intermeshed teeth of gears 92 and 91. Lead screw 98is operatively connected to gear 92 so that rotation of gear 92 causesrotation of lead screw 98 in the same direction. The power pack 90 insome embodiments can include a power switch which is activated, i.e.,turned on, by the clinician to start the motor and effect articulation.

Connected to the end of lead screw 98 (the end opposite the connectionto the gear 92) is a drive mechanism 95 configured to move in a linearmotion (in an axial direction) along the lead screw 98 in response torotation of the lead screw 98. For example, the drive mechanism 95, likedrive mechanism 40 described above, may include internal threads thatengage external threads of the lead screw 98 and may include slidesengaged in a track that prevent the drive mechanism 95 from rotating andtherefore cause the drive mechanism 95 to move linearly (axially) inresponse to rotation of the lead screw 98. As depicted, the power pack90 has a compact configuration as the lead screw 98 extends alongside,slightly spaced from, the motor 96 and gear box 93, i.e., both the motor96/gear box 93 and lead screw 98 extending longitudinally with the leadscrew 98 parallel to the motor 96. The drive mechanism 95 is connectedto a proximal end of lead screw 98. The drive mechanism 95 has anarticulation rod engagement feature in the form of a flange or yoke 94extending therefrom having legs 99 b and a recess 99 a to engage anarticulation rod 79 movable within the elongated member 51 of theloading unit. In the illustrated embodiment, the articulation rod 79includes a flange or boss 78 which is engageable by the flag 94. Theoutput flag 94 can engage the bossed end 78 of the articulation tube 79in substantially the same manner as the output flag 42 engages thebossed end 44 of the firing rod 46 as discussed above.

The articulation assembly of the power pack 90 is oriented in theopposite direction from the staple firing assembly to minimize the spacerequired in the power pack 90, thereby providing the power pack with acompact configuration. As can be appreciated by reference to FIG. 9D,the drive assembly 80 and associated flag 82 are at a proximal end ofthe assembly for firing staples with the lead screw 86 extendingdistally toward the gears 81, 84. The driving assembly 95 withassociated flag 94 of the assembly for articulation are at a distal endwith the lead screw 98 extending proximally toward gears 91, 92. Also,as can be appreciated by reference to the orientation of FIG. 9D, thearticulation assembly is above the firing assembly, and the articulationassembly in the illustrated embodiment is positioned axially proximal ofgears 81, 84 and axially distal of drive mechanism 80, radially spacedfrom lead screw 86.

The power pack 90, like power pack 35 can have features/structure toconstrain the motors 84 and 96. These include for example spaced apartproximal and distal rails like proximal and distal rails 97 a, 97 b ofFIG. 9B, wherein gear box 93 can be seated within the proximal rails andthe motor can be seated within the distal rails, the rails retaining themotor and preventing axial and rotational movement within the housing ofpower pack 90. Bearing or bushings like bushings 71 a, 71 b of FIG. 8Fcan also be provided to constrain the lead screw 98 at opposing ends,while allowing rotation thereof, thereby also constraining the motor.Other features can additionally or alternatively be provided to restrainthe motor from axial movement while allowing rotation of the lead screw.

Upon loading of the power pack 90, the flag of the drive mechanism 80 ofthe staple firing assembly engages flange 76 of firing rod 75 and flag94 of drive mechanism 95 of the articulation assembly engages flange orbossed end 78 of articulation rod 79. Actuation of the motor 96 effectslinear motion of the flag 94 which moves the articulation rod 79linearly (axially). The articulation rod 79 is either directly coupledto the joint 54, or coupled to another member or multiple members whichare coupled to the joint 54. When moved linearly, the articulation rod79 effects movement of the jaws 52 a, 52 b of the stapler 10 to angularpositions with respect to the longitudinal axis of the stapler. Note thearticulation drive assembly operates in a similar manner as the firingdrive assembly of power pack 35 in that when the power pack 90 issecured to the tube 79 by the second output flag 94, linear motiongenerated at the second output flag 94 is transferred to linear motionof the tube 79. Note that the joint 54 could be configured to providemovement about multiple axis, e.g., two or three axes, and could even beconfigured to provide unconstrained movement.

Actuation of the motor 83 effects linear motion of the flag of drivemechanism 80 which moves the firing rod 46 linearly (axially). Thefiring rod either extends through the elongated portion 51 of theloading unit 50 for engagement of the firing mechanism in the jaw 52 aor is coupled to another elongated component(s) extending through theelongated portion 51 to engage the firing mechanism in the jaw 52 a.Note that the articulation rod or tube 79 can be configured to receivethe firing rod so that the firing rod 46 can move within the tube 79 toeffect firing and the articulation rod 79 can slide linearly over thefiring rod to effect articulation.

After use, the cover can be opened and the power pack 90 removed andcharged while the handle assembly 17 (and stapler 10) is sterilized ordisposed of if the stapler is a disposable instrument. The power pack90, like power pack 35 described above, may be reused without requiringsterilization by being inserted into the receptacle of thenow-sterilized handle assembly or a different sterile handle assembly.Thus, the removable power pack 90, like power pack 35, does not need tobe subjected to the sterilization process and, therefore, contactbetween the harsh temperatures and/or chemicals of the sterilizationprocess is advantageously avoided.

One or more seals can be utilized for sealing power pack 35 and powerpack 90 within the handle assembly 17 so that the power pack remainssterile and is not exposed to bodily fluids during surgical procedures.For example, as discussed above, in the stapler of FIG. 2B, a top sealis positioned at the interface between the cover 27 a and the housing 29of the handle assembly where the cover 27 a closes for sealing theopening into the receptacle 27 b and, therefore, power pack 35 or 90from the environment when positioned therein. Further seals can beprovided to further seal the receptacle and thus the power pack such asan O-ring placed around the articulation rod 79 to seal the space aroundthe rod 79 and a flexible trigger seal surrounding the lever of theactuator 24′ for sealing the internal components of the handle assemblythroughout the range of positions of the movable lever 24′. Additionalseals can be provided to prevent flow of body fluid through theelongated member 51 and endoscopic portion 16.

As noted above, the power pack 90 can be used with the other staplersdisclosed herein, e.g. circular staplers, linear staplers, as well asother instruments wherein two powered functions are desired. The firstmotor assembly can effect linear motion of a first elongated member toeffect a first function of the stapler, e.g., clamping, articulation,firing, and the second motor assembly can effect linear motion of asecond elongated member to effect a second different function of thestapler, e.g., clamping, articulation, firing. In the embodiment of FIG.9D, one function is articulation and another function is staple firing.Note the power pack 90 can also be used with surgical instruments otherthan surgical staplers such as those illustrated in FIGS. 16 and17A-17F.

The proximally loaded loading units of the present disclosure caninclude various end effectors to achieve various functions. They can beoffered in a kit containing two or more differently functioning loadingunits, i.e., differently functioning jaws. FIG. 16 provides one exampleof a kit having two loading units: Loading unit 170 has a pair ofscissors and loading unit 175 has a pair of graspers. More specifically,loading unit 170 has a handle portion 171, an elongated portion 172 andjaws 173 a, 173 b which are connected to a clamping member extendingthrough elongated portion 172. Movement of the clamping member (clampingrod) within the elongated portion 172 moves the jaws 173 a, 173 bbetween open and closed positions to cut tissue between the jaws 173 a,173 b. Loading unit 175 has a handle portion 176, an elongated portion177 and jaws 178 a, 178 b which are connected to a clamping memberextending through elongated portion 177. Movement of the clamping member(clamping rod) within the elongated portion 177 moves the jaws 178 a,178 b between open and closed positions to grasp tissue between the jaws178 a, 178 b. The jaws 178 a, 178 b can have grasping surfaces that caninclude teeth, roughened surfaces, ribs, etc.

The loading units 170 and 175 are insertable and removable through aproximal opening 195 in the instrument 190 (as in proximal openings 23and 29 a described above) while the instrument remains in the body. Theinstrument 190 can be manually actuated, i.e., by squeezing handle 194towards handle 196, to effect clamping of the jaws of the loaded loadingunit when inserted into the instrument 190, as handle 192 operativelyengages the clamping member to effect its linear movement. Thisengagement can be via a rack and pawl as in FIG. 15. Alternatively, theinstrument 190 can be powered by a power pack loaded into thecompartment of the stapler in the same manner as power pack 30 or 35described below, with the proximal opening within the compartment. Thepower pack drive mechanisms, e.g., an output flag or yoke like flag 42,would extend through the slot in handle portions 171, 176 to engage theclamping member within the loading unit to effect movement of the jawstoward each other. Either one of the jaws can be movable, i.e.,pivotable, or both jaws can be movable (pivotable) toward and away fromeach other, for movement between closed and open positions

It should be appreciated that FIG. 16 is just one example of a kit askits with other combinations of loading units, (and any number ofloading units) including loading units containing fasteners, can beprovided which are proximally loaded into the instrument in the samemanner as loading unit 50 so that various loading units, or loadingunits that are reloaded with fasteners, can be removed and reinsertedwhile the instrument remains in situ. Alternate jaw assemblies of theproximally loaded loading units are shown in FIGS. 17C-17F by way ofexample, it being understood that other jaw assemblies could beprovided. Jaw assembly 180 provides shears for dissecting tissue, jawassembly 182 provides graspers to grasp tissue, and jaw assembly 184 isa bipolar dissector to provide electrosurgical energy to tissue graspedbetween the jaws. In FIG. 17D, instead of jaws, a hook 186 for monopolarcautery extends from the elongated member of the proximally loadedloading unit. In FIG. 17E, the jaws 188 crimp a surgical clip 189 abouttissue. In FIG. 17F, the proximally loaded loading unit has an advancerwithin the elongated member to apply surgical tacks to tissue.

It should be appreciated that the aforedescribed variations of the powerpacks can also be used with the surgical instruments of FIGS. 16-17F soone or more functions can be powered by the motor. Alternatively, theinstruments of FIGS. 16-17F can be manually powered.

The power packs disclosed herein can be used in surgery where theclinician manually clamps the jaws and actuates the motor or motors toprovide powered staple firing and/or powered jaw articulation or otherfunctions. It is also contemplated that the power packs 30, 35 and 90can be used with automated robotic driven surgical staplers whereinclamping, motor actuation and any other functions of the instrument areperformed robotically, including remote robotic control. This is shownfor example in FIGS. 6C and 6D. Robotic arm 160 has a base 162 that isrotatable 360 degrees, an arm 164 connected to the base which moves in aclockwise or counterclockwise direction, and an arm 166 extending fromarm 164 which swivels in a motion simulating a person's wrist to providevarious degrees of freedom to manipulate the stapler. In FIG. 6C, thestapler is shown held in arm 164 of robotic arm 160 prior to proximalloading of the loading unit 50 (or other loading units described herein)into the stapler 168 (which can be identical to stapler 10 or otherstaplers disclosed herein). FIG. 6D illustrates the stapler 168 afterthe loading unit 50 (or other loading units described herein) areproximally loaded into the stapler 168. The degrees of freedom of thearms and base described herein are one example of the robotic arm designthat can be utilized as other movements for the base and arms are alsocontemplated. The robotic arm can also be utilized for the otherinstruments disclosed herein, e.g., circular staplers, scissors,graspers, etc.

Thus, whether robotically positioned or manually positioned by the user,the present disclosure provides a method for reloading a surgicalfastener applier wherein the surgical fastener applier is maintained ina body, e.g., body cavity of a patient, while a) a first loading unit isproximally withdrawn through a proximal opening in the surgical fastenerapplier and b) a second loading unit is inserted in a distal directionthrough the proximal opening in the surgical fastener applier. Theloading units each have an elongated member, first and second jaws at adistal portion of the elongated member and a firing mechanism movablewithin the elongated member from a first position to effect firing offasteners into the tissue clamped between the first and second jaws. Theloading units can alternatively have other jaws, e.g., graspers,scissors, etc. for effecting different surgical functions.

In some embodiments, elements such as the rotational member and handleactuator may be omitted and a controller may be configured to generatesignals or commands to be received by the surgical stapler in order toactuate the jaws, rotate the tubular shaft or perform other functions.Such a controller may be part of the surgical stapler device or locatedremotely.

The handle assembly and/or motor assembly may be in wired or wirelesscommunication with an external controller that includes inputs forcontrolling the surgical stapler

Although the apparatus and methods of the subject disclosure have beendescribed with respect to preferred embodiments, those skilled in theart will readily appreciate that changes and modifications may be madethereto without departing from the spirit and scope of the presentdisclosure as defined by the appended claims.

What is claimed is:
 1. A method for reloading a surgical fastenerapplier comprising the steps of: a) with the surgical fastener appliermaintained in a body of a patient, withdrawing a first loading unit in aproximal direction through a proximal opening in the surgical fastenerapplier, the loading unit having an elongated member, first and secondjaws at a distal portion and a firing mechanism movable within theelongated member to effect firing of fasteners into the tissue clampedbetween the first and second jaws; and b) with the surgical fastenerapplier maintained in the body of the patient, inserting a secondloading unit in a distal direction through the proximal opening in thesurgical fastener applier, the second loading unit having an elongatedmember, first and second jaws at a distal portion and a firing mechanismmovable within the elongated member to effect firing of fasteners intothe tissue clamped between the first and second jaws; c) wherein thefiring mechanism is powered by a motor, the motor contained in a powerpack removably mounted in a sealable compartment of the surgicalfastener applier, the power pack having a housing containing the motorand a battery d) wherein the second loading unit operatively connects toa first actuator within the surgical fastener applier for firing thefasteners and includes an articulation mechanism and the articulationmechanism is engageable with a second actuator within the surgicalfastener applier; e) wherein the second actuator is powered by a secondmotor, the second motor contained in the power pack removably mounted inthe surgical fastener applier.
 2. The method of claim 1, wherein thepower pack includes an engagement member, the engagement memberremovably engageable with the articulation mechanism in the loading unitto effect articulation of the first and second jaws from a linearposition to a position angled with respect to a longitudinal axis of theelongated member when the power pack is loaded into the compartment. 3.The method of claim 1, wherein the second loading unit has a differentstructure than the first loading unit removed from the surgical fastenerapplier.
 4. The method of claim 1, wherein the loading unit has anengagement structure engageable with a side wall of a housing of thesurgical faster applier to retain the loading unit.
 5. The method ofclaim 1, wherein the elongated member of the second loading unit has anelongated slot to receive an engagement member of the power pack forengagement of a drive mechanism of the power pack with the firingmechanism of the second loading unit.
 6. The method of claim 1, whereina housing of the surgical faster applier has a lumen extendinglongitudinally distally from the proximal opening and the second loadingunit is insertable through the lumen in the housing.
 7. The method ofclaim 1, wherein the first loading unit includes a cartridge containingthe fasteners, the method includes removing the cartridge from the firstloading unit after firing and replacing with another cartridge havingfasteners.